WO2011107081A1

WO2011107081A1 - Guide gib

Info

Publication number: WO2011107081A1
Application number: PCT/DE2011/000218
Authority: WO
Inventors: Karl-Heinz Wenzelburger; Jürgen WENZELBURGER
Original assignee: Botek Präzisionsbohrtechnik Gmbh
Priority date: 2010-03-05
Filing date: 2011-03-03
Publication date: 2011-09-09
Also published as: EP2542369B1; US20130051944A1; US9358620B2; DE202010003288U1; EP2542369A1

Abstract

A guide gib (500) for a deep drilling tool of a substantially rectangular shape with a longitudinal direction (L) and a width (B) and with at least one sliding surface (540) is characterized in that at least one lubricating groove, preferably a plurality of lubricating grooves (501, 502), is/are arranged at least in the region of a contact zone of the sliding surface.

Description

guide rail

State of the art

The invention relates to a guide rail according to the species of

independent claim 1.

Guide rails are in a seat on a drill head of a

Attached deep drilling tool. The fastening can be effected detachably or exchangeably (for example by means of screws) or also by material engagement (for example by soldering or gluing). A guide rail has at least one sliding surface provided therewith with the bore wall

co. The most common systems for deep drilling are the single-lip drilling system, the so-called BTA (Boring and Trepanning Association) system, also known as STS (Single Tube System), and the ejector system. An overview is provided by the VDI guideline VDI3210.

In these deep drilling systems, a cooling lubricant is usually used, on the one hand to lubricate and cool cutting edges and guide rails, and on the other hand, the chips produced during machining

CONFIRMATION COPY to flush out of the hole. Deep hole drilling tools are mainly used to make large bore holes relative to

Drilling diameter used. Typical values for the drilling depth are in the range of 10 times to 100 times the drilling diameter, but may also be above or below it.

In deep drilling tools guide rails are used to support the resulting cutting forces against the bore wall and the

To guide deep drilling tool in the hole. This drilling can be produced, which is characterized by a particularly good straightness

distinguished. In addition, the bore surface is smoothed by the guide rails sliding thereon.

Guide rails are usually made of carbide. They can also be made of other wear-resistant materials such as ceramic or CBN or other suitable materials.

There are also known guide rails, which consist of a steel body in which elements of wear-resistant material are attached, which then in turn contact the bore wall in contact. In addition, there are guide rails, the sliding surface is divided into several areas, between which recesses may be arranged.

Guide rails slide over the bore wall during the drilling process. Usually only a part of its sliding surface abuts the bore wall. Inadequate cooling and / or lubrication by the coolant in this contact zone, the friction between the guide rail and

Bore wall be very high, which can cause very high temperatures.

A well-known problem caused by the high temperatures is cracking in the guide rails. This occurs mainly on guide rails made of carbide. The at high

Temperatures arising cracks can progressively

Continue to stretch the load. This can lead to breakouts or breakage of the guide rail, which can damage the bore surface. This damage can lead to the workpiece having to be reworked or no longer usable. Cracking occurring on the guide rails is therefore undesirable and should be avoided as far as possible.

In DE 600 14 923 T2, a guide rail is disclosed which has a planar depression or depression in the region of the sliding surfaces, whose

Extend an angle of 55 ° + 10 ° with the longitudinal direction of the

Includes guide rail. This reduction is comparatively wide and executed deep in relation to the dimensions of the guide rail and should allow the coolant to flow through this reduction. As a result, a particularly good cooling of the sliding surface or contact surface is to be achieved, whereby the cracking is to be reduced.

The reduction in this known guide rail is comparatively wide, the sliding surfaces are arranged on the edge. Although this training allows optimal coolant passage, nevertheless sufficient lubrication in the area of the contact surfaces is not guaranteed to the full extent. Namely, the cooling lubricant is supplied only along the lateral boundary surfaces in this case. To the

Contact surfaces themselves, however, can reach coolant only with difficulty.

The invention has for its object to provide a guide bar, through which a much improved lubrication in the

Contact surfaces and in particular in the region of the contact zones, which are in contact with the bore wall, is reached, so that the risk of cracking is reduced, thereby extending the life of the guide rail. This object is achieved by the features specified in the independent claim 1.

Disclosure of the invention

The basic idea of the invention is to arrange recesses or lubrication channels on its sliding surface in the case of a guide strip, so that a significantly better lubrication at the contact zone between the guide strip and the bore wall is ensured.

The arrangement of the lubrication channels directly in the sliding surface is a significantly higher life compared to previously known

Guides reached. In experiments it has been found that the life span of inventive guide rails can be more than twice the service life of known guide rails.

The improvement is due to the arrangement of lubrication grooves in the

Sliding surface of the guide rails achieved, the expansion in width and depth is small compared to the width and thickness of the guide rail. Along this lubrication cooling lubricant can be supplied to different locations of the sliding surface or the cooling lubricant can collect in such Schmiemuten and thus contribute to lubrication, whereas in known guide rails only on the lateral boundary surfaces

Enter coolant and can be passed to the contact zone.

Advantageous embodiments and embodiments are the subject of the dependent claims on claim 1. Thus, according to an advantageous embodiment, it is provided that the lubrication grooves have an angle of less than or equal to 45 ° or greater than 75 ° to the longitudinal direction. Due to experiments carried out has been particularly advantageous an arrangement of several parallel Schmiemuten in one Angle of both approximately 90 ° and parallel to the longitudinal extent of the guide bar proven. Furthermore, improvements could also be achieved with lubrication grooves, which were arranged at an angle of approximately 30 ° to the longitudinal direction of the guide rail. The lubrication grooves can purely in principle in the most diverse ways in the

Guide rails are arranged. An advantageous embodiment provides that the lubrication grooves open into the boundary surfaces which limit or limit the guide strips both in their width and in their length. As a result, a continuous cooling lubricant supply is ensured. Yet another embodiment provides that the lubrication grooves are designed as closed pockets, i. are limited in terms of their length and width in the region of the sliding surface of the guide rail. The pocket-shaped design of the lubrication grooves has the advantage of a reservoir formation for the cooling lubricant. It can be provided that the length and width of the lubrication grooves in

Substantially match, so that the pocket-shaped lubrication have a square base. In addition, circular or oval base surfaces may be provided. Such a design of the lubrication grooves is particularly below

Manufacturing aspects advantageous.

With a view to optimum lubrication, lubrication grooves are advantageous whose width is small compared with the width of the guide rail. Lubricating grooves have proved to be advantageous, the width of which corresponds to a maximum of one fifth of the width of the guide rail.

The lubrication grooves themselves may, in principle, have a wide variety of shapes. In addition to a polygonal, an arcuate or any irregular shape may be provided. Also combinations of these forms are possible. The lubrication grooves themselves have only a small depth. It has proved to be advantageous to have a depth of the lubrication grooves which is between 0.1 mm and 1.5 mm.

To increase the service life of the guide rails is provided that they at least partially made of hard metal. In addition, it can also be provided that the guide rails are coated with a hard material layer.

drawings

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

Show it:

Fig. 1a a drill head of the BTA drilling system with three interchangeable

fixed guide rails;

1b shows a drill head of the ejector drilling system with two material fit

fixed guide rails;

Fig. 2 is a drill head of a Einlippenbohrers with two interchangeable

fixed guide rails;

3a shows a guide strip according to the prior art;

3b shows a further guide strip according to the prior art in

multipart design and with a reduction between the

sliding surfaces;

Fig. 4 shows the typical contact zone of a guide rail according to the prior art;

5 shows an embodiment of a guide strip according to the invention with a plurality of longitudinal and transverse lubrication grooves;

Fig. 6 is a plan view of the guide strip shown in Fig. 5; 7 shows an embodiment of a guide strip according to the invention with a plurality of diagonally extending lubrication grooves;

Fig. 8 is a plan view of the guide bar shown in Fig. 7;

9 shows an embodiment of a guide strip according to the invention with a plurality of pocket-like closed lubrication grooves.

FIG. 10 is a plan view of the guide bar shown in FIG. 9; FIG.

11 shows a cross section of an embodiment of a lubricating groove of a guide strip according to the invention;

12 shows a cross section of a further embodiment of a lubricating groove of a guide strip according to the invention;

13 shows a cross section of a further embodiment of a lubrication groove of a guide strip according to the invention.

Description of exemplary embodiments

FIG. 1a shows an isometric view of a drill head 100 for the so-called BTA drilling system, which has three interchangeably mounted ones

inventive guide rails 110 is equipped. The

Guide rails 110 are fastened with screws 120 on the drill head 100, so that they can be turned after their service life or exchanged for new guide rails 110. The life of the drill head 100 may be a multiple of the life of the guide rails 110.

Furthermore, two cutting plates 130, 132 fastened with screws are arranged on the drill head 100. The drill head 100 has two openings 140 which are connected to an inner channel. About these openings 140 and the inner channel, the chips produced during drilling are removed. At one end of the drill head 100 is provided with a receptacle 190, by means of which it is connected to a (not shown) boring bar in a known per se. Both the number and arrangement of the cutting plates 130, 132 and the openings 140 and channels and the Design of the receptacle 190 for the boring bar are irrelevant to the present invention.

FIG. 1b shows an isometric view of a drill head 101 for the ejector drilling system, which is equipped with two guide strips 111 fastened in a materially bonded manner. Furthermore, three cohesively mounted cutting plates 160, 161, 162 are arranged on the drill head 101. The life of such a drill head 101 is usually reached when either the

Guide rails 111 or the cutting plates 160, 161, 162 have reached the end of their life. The drill head 101 has two openings 141, which are connected to an inner channel. About these openings 141 and the inner channel resulting in drilling chips are removed. At one end of the drill head 101 is provided with a receptacle 191, by means of which it is connected to a (not shown) boring bar. Both the number and arrangement of the cutting plates 160, 161, 162 and the openings and channels as well as the configuration of the receptacle 191 for the boring bar are irrelevant to the present invention.

FIG. 2 shows an isometric view of a drill head 200 of a

Single-lip drill equipped with two replaceably mounted guide rails 210. The guide rails 210 are fastened with screws 211.

In addition, the drill head 200 is equipped with an exchangeable by means of a screw mounted cutting plate 220. It also has an inner channel 230 for the supply of cooling lubricant and an outer groove 231 for removing the chips and the coolant produced during drilling. The number and arrangement of

Cutting plates 210 and the arrangement of the channel (s) are immaterial to the present invention. FIG. 3a shows an isometric view of a prior art guide rail 300. The guide rail 300 typically has two planar side surfaces 320 delimiting the longitudinal extent L, two planar side surfaces 310 delimiting the width B and a flat bottom surface 330 and a curved sliding surface 340 having the thickness H of the

Limit guide bar 300. With the bottom surface 330 and the

Side surfaces 310, 320, the guide bar 300 is located at a

corresponding seat in the drill head, whereby the position of the guide bar 300 is defined in the drill head. The curvature of the sliding surface 340 is advantageously designed so that its radius of curvature is less than or approximately equal to the radius of the bore to be produced. The

The axis of curvature of the sliding surface is preferably aligned approximately parallel to the axis of rotation of the drill head, which runs substantially parallel to the longitudinal sides 310 and the bottom surface 330.

Figure 3b shows an isometric view of another typical

Guide rail according to the prior art. This guide rail 301 corresponds to that of Figure 3a, with the difference that the

Guide bar 301 is constructed of several parts, which are interconnected. Preferably, such guide rails are constructed from a first part of a first inexpensive material, such as steel, and at least one other part of wear-resistant material, such as hard metal, by means of a

cohesive bonding methods, for example, by soldering, are connected together. The guide strip shown in the figure has two sliding surfaces 341, 342, between which a recess 350 is arranged. The sliding surfaces 341, 342 are doing by the

wear-resistant material is formed. For the curvature of the sliding surfaces 341, 342, what has been said above in connection with FIG. 3a applies correspondingly.

FIG. 4 shows a plan view of the sliding surface 340 of FIG. 3a

shown guide bar 300. Hatched is the typical Contact zone 390 on the sliding surface 340 of a guide rail 300, which usually occurs when drilling with deep hole drills wear. This contact zone 390 corresponds to the part of the sliding surface 340 of the guide rail 300, which is actually in contact with the bore wall (not shown). In this area, friction occurs between the sliding surface 340 and the bore wall, that is to say a material removal on the guide rail 300. In the contact zone 390, the guide rail 300 bears directly against the bore wall, as a result of which only very little cooling lubricant reaches between the contact zone 390 and the bore wall can. With increasing wear, the surface of the contact zone 390 becomes larger and cracks can form in this zone, which can be caused by persistent

Heat effect caused.

Usually, wear occurs only on one side of guide rails, so that the guide rails can be turned by 180 ° and used again.

Guide rails known in the art are typically fabricated, at least in the region, of a wear resistant material in contact with the bore wall. Common materials for this purpose are, for example, carbide, ceramic or CBN. To further increase the life may also be provided to coat at least the sliding surface (s) of a guide bar with a hard material layer, both the formation of wear and the

Transfer of heat into the guide rail is reduced as well as the friction between the sliding surface and the bore wall is reduced.

FIG. 5 shows an isometric view of a device according to the invention

Guide bar 500 with the same structure as the guide rails shown in Fig. 3a and 4. As can be seen from FIG. 5, a plurality of lubrication grooves 501, 502 are arranged along the sliding surface 540 of the guide rail 500, which run parallel to the lateral boundary surfaces 510, 520 of the sliding surface 540 and open into them. FIG. 6 shows a plan view of the sliding surface of the guide strip shown in FIG. 5. The typical contact zone 590 is shown as a dashed line. The lubrication grooves 501, 502 are arranged in the region of the contact zone 590. Along the lubrication grooves 501, 502, which are also connected to each other, can reach when contacting cooling lubricant in the contact zone 590, whereby a significantly improved lubrication between

Contact zone 590 and bore wall is achieved. The friction between the guide rail 500 and bore wall in the contact zone 590 is thereby significantly reduced. Tests have shown that this arrangement of lubrication grooves 501, 502 significantly reduces both cracking and wear compared to guide rails without lubrication grooves. Such guide rails thereby have a much higher

Life as known from the prior art guide rails.

In contrast to the guide rail known from DE 600 14 923 T2, the lubrication channels provided here are not arranged between the sliding surfaces but pass through them in order to ensure better lubrication in the contact zone 590. In the case of the guide rails known from DE 600 14 923 T2, by arranging a depression between the sliding surfaces by means of the cooling lubricant flowing therethrough

Cooling of the guide bar achieved. In contrast, in the guide strip shown in Figure 5 and Figure 6, the lubrication channels 501, 502 arranged so that they pass through the contact zone in a sense, and thus lead to improved lubrication in the contact zone 590. In addition, the extent of the lubrication channels 501, 502 compared to those known from the prior art is very small, since even small amounts of cooling lubricant are sufficient to improve the lubrication, whereas significantly larger amounts of cooling lubricant are needed for cooling. FIG. 7 shows an isometric view of a further guide strip 700 with the same structure as that shown in FIGS. 3 a and 4. Here are along the sliding surface 740 of the guide rail 700 a plurality of lubrication grooves 701st

arranged, which extend at an angle to the lateral boundary surfaces 710, 720 along the sliding surface 740 and in the

Boundary surfaces 710, 720 open.

FIG. 8 shows a plan view of the sliding surface 740 of FIG. 7

Guide rail 700. The lubricating grooves 701 are arranged at the angle w to the lateral boundary surfaces 710, 720. The contact zone 790 is shown as a dashed line. The lubrication grooves 701 allow optimum lubrication in the region of the contact zone 790.

FIG. 9 shows an isometric view of a further guide strip 900 with the same construction as that shown in FIGS. 3 a and 4. In the sliding surface 940 of the guide rail 900 a plurality of pocket-like lubrication grooves 901 are arranged, which extend along the sliding surface 940. In contrast to the embodiments shown in Figure 5 to Figure 8 lead to the

Lubricating grooves 901 but not in the lateral boundary surfaces 910, 920, but are limited in their extent solely on the sliding surface 940. This embodiment of the lubrication grooves 901 acts as a reservoir in which cooling lubricant can collect, so that there is always a small amount of cooling lubricant that can contribute to the lubrication in the contact zone 990.

FIG. 10 shows a plan view of the sliding surface 940 of FIG. 9

illustrated guide rail 900. The contact zone 990 is shown as a dashed line. The length of a lubricating groove 901 is denoted by C. In principle, the length of each lubrication groove 901 may be different than the length of the other lubrication grooves 901. Other embodiments of lubrication grooves may, for example, an arcuate or polygonal course in the plan view of the

Have guide strip. However, the subject of the present invention is not the embodiment of the lubrication grooves themselves, but the arrangement of the lubrication grooves in the region of the contact zone between the guide rail and the bore wall. The representation of the lubrication grooves shown in Figure 5 to Figure 10 is for this reason not restrictive to understand. In principle, any formations and shapes of the

Lubricating be provided, these lubrication grooves are always located in the region of the contact zone and compared to the

Limiting surfaces and the height or thickness of the guide strips have small dimensions.

FIGS. 11 to 13 show various preferred embodiments for the cross section of the lubrication grooves. The illustrated

Embodiments relate to the cross-sections shown in Figure 6 with X-X, in Figure 8 with Y-Y and in Figure 10 with Z-Z.

FIG. 11 shows a substantially rectangular cross-section of a lubrication groove N.

FIG. 12 shows a substantially arcuate cross section of a lubricating groove NT.

FIG. 13 shows a substantially triangular cross-section of a lubricating groove N ".

In FIG. 11 to FIG. 13, the width of the lubricating groove is in each case designated as A, the depth of which is designated T. The depth T is preferably between 0.1 and 1.5 mm. The lubrication grooves N, Ν ', N "can either be produced by a primary molding process during the production of the guide strips, for example by pressing and sintering, or they can be introduced into the sliding surface in a separate operation.

The illustrated cross-sectional shapes are shown here by way of example only. All other possible cross-sectional shapes, including irregular or polygonal, are possible in principle. The invention thus also encompasses any embodiments of the lubrication grooves.

Tests have shown that a particularly significant improvement in the life of the guide rails could be achieved if several lubrication grooves were introduced at an angle of both approximately 90 ° and parallel to the longitudinal extent of the guide strip. In addition, improvements could also be achieved with lubrication grooves which were arranged at an angle of approximately 30 ° to the longitudinal direction of the guide rail.

In principle, improvements can also be achieved by providing lubrication grooves according to FIG. 9 and FIG. 10 whose expansion in width and length is at least approximately the same. Accordingly, the lubrication grooves could, for example, in the plan view according to FIG. 10, be embodied as a circular or square recess, wherein the cross-sectional shape can preferably be designed in accordance with FIG. 11 to FIG.

Claims

claims

1. Guide bar (500, 700, 900) for a deep drilling tool with

at least one sliding surface (540, 740, 940), characterized in that at least one, preferably a plurality of lubrication grooves (501, 502, 701 ; 901) is arranged.

2. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the lubrication grooves (501, 502; 701; 901) make an angle of less than or equal to 45 ° or greater than 75 ° to a

Longitudinal direction (L) of the guide strip (500, 700, 900) have.

3. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the lubrication grooves (501, 502; 701; 901) open into the boundary surfaces which limit the width of the guide strip (500; 700; 900) (B).

4. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the lubrication grooves (501, 502; 701; 901) open into the boundary surfaces which limit the length of the guide strip (500; 700; 900) (L).

5. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the lubrication grooves (501, 502; 701; 901) are designed as closed pockets.

6. guide strip (500; 700; 900) according to claim 5, characterized

characterized in that the lubrication grooves (501, 502; 701; 901) have a length (C) approximately equal to their width (A).

7. guide strip (500; 700; 900) according to claim 1, characterized

in that the lubrication grooves (501, 502; 701; 901) each have a width that corresponds to a maximum of one fifth of the width (A) of the guide strip (500; 700; 900).

8. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the lubrication grooves (501, 502; 701; 901) have a polygonal and / or arcuate and / or an irregular shape.

9. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the depth of the lubrication grooves (501, 502; 701; 901) is between 0.1 mm and 1.5 mm.

10. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the guide strip (500; 700; 900) consists at least partially of hard metal.

11. guide strip (500; 700; 900) according to claim 1, characterized

characterized in that the guide strip (500; 700; 900) is provided with a hard material layer.